Machining off block numbers
Thread Starter
Pro
Joined: Jan 2017
Posts: 653
Likes: 51
From: Beaver County PA
Machining off block numbers
I'm rebuilding the original engine in my 72. My machinist says the block needs decked and since its not the first rebuild of the engine he believes the block numbers will be machined off. The engine is numbers matching and I would like to keep them. Can I have the numbers re-stamped. Is there a way I can have it verified? Would pictures help? Any help is appreciated.
Mike.
Mike.
Race Director
Joined: Mar 2003
Posts: 11,608
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From: Eustis ( Area 51 Bat Cave ) Fl
I'm rebuilding the original engine in my 72. My machinist says the block needs decked and since its not the first rebuild of the engine he believes the block numbers will be machined off. The engine is numbers matching and I would like to keep them. Can I have the numbers re-stamped. Is there a way I can have it verified? Would pictures help? Any help is appreciated.
Mike.
Mike.
A restamp is just that, seems ( to me ) it doesnt matter at that point what block the restamp is on, its not the factory stamp.
Race Director
Joined: Mar 2016
Posts: 14,336
Likes: 8,140
From: Napa Valley California
Is your model rare?
Besides the wheels has anything else been replaced or modified?
Are you swapping heads, intake, carb, etc from original?
Will it matter to the next buyer?
In ten years will anyone even want the original motor or will the hot ticket be to ditch the original and replace it with something newer and better than an LS motor?
If it's important to you, buy another block save all the original parts and enjoy your new non original motor.
Besides the wheels has anything else been replaced or modified?
Are you swapping heads, intake, carb, etc from original?
Will it matter to the next buyer?
In ten years will anyone even want the original motor or will the hot ticket be to ditch the original and replace it with something newer and better than an LS motor?
If it's important to you, buy another block save all the original parts and enjoy your new non original motor.
Burning Brakes
Joined: Jan 2017
Posts: 1,095
Likes: 213
From: The Buckle of the Bible Belt. Joplin Mo
Im a modder so not my area of concern but ive read on here that a "good" machinist can do a block without hurting the born with stamp, if thats true then a person into numbers would have to go that way.
A restamp is just that, seems ( to me ) it doesnt matter at that point what block the restamp is on, its not the factory stamp.
A restamp is just that, seems ( to me ) it doesnt matter at that point what block the restamp is on, its not the factory stamp.
Good luck with your build Mike, regardless of your decision.Ray
Thread Starter
Pro
Joined: Jan 2017
Posts: 653
Likes: 51
From: Beaver County PA
The engine, trans and frame are all numbers matching and I would like to keep it that way. However, I am replacing the iron heads (keeping the originals) with aluminum, the intake (with aluminum) and points distributor with an HEI. The intake that came with the car when I bought it is not original and there are no numbers on the dizzy which makes me believe it also is not original. I am not having the car judged, just a cruiser, and I don't plan on selling. It will be handed down to my sons along with my 1979 Z28 and they can do whatever they want with them. So if its not a major ordeal to have them re-stamped then I'm in, but its a hassle then I guess I'll just let it go. Just looking for some input from all your experience.
Drifting
Joined: Jul 2011
Posts: 1,697
Likes: 139
From: Syracuse NY
The engine, trans and frame are all numbers matching and I would like to keep it that way. However, I am replacing the iron heads (keeping the originals) with aluminum, the intake (with aluminum) and points distributor with an HEI. The intake that came with the car when I bought it is not original and there are no numbers on the dizzy which makes me believe it also is not original. I am not having the car judged, just a cruiser, and I don't plan on selling. It will be handed down to my sons along with my 1979 Z28 and they can do whatever they want with them. So if its not a major ordeal to have them re-stamped then I'm in, but its a hassle then I guess I'll just let it go. Just looking for some input from all your experience.
PS- Im not shi++on your idea, Im just telling you to invest your time and money into making this a fun car to drive. In 10 years, nobody will care that your moderately modded, overbored, cammed, high flow heads and header equipped engine has a number on it that matches the VIN plate.
Bottom line up front- unless its ALL ORIGINAL and TOGETHER like it came from the factory, dont bother. Invest your time and money on 1) paint 2) performance parts, as they will yield a FAR better return than a 'semi' original car.
Team Owner
Joined: Jun 2000
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From: Southbound
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Team Owner
Joined: Oct 2004
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From: altered state
St. Jude Donor '05
With scott
Yes it can be restamped...there are machinists that can deck it and keep the #s usually a CNC program
If it needs to be decked then just do it. If you put the block away I doubt it will make its way inside the car again.
Ive seen guys get too carried away and actually reuse the old pistons in a worn out bore cause "well its original", "value" etc. Good gawd.
Gimme a good proper rebuild anyday over that. I kept my 73 all # match didnt enjoy ownership..it meant spit when I sold it.
Buyer said "I could care less" and saw his point. 2 mos later he had a new motor, paint etc and sold it for much more a year later.
Yes it can be restamped...there are machinists that can deck it and keep the #s usually a CNC program
If it needs to be decked then just do it. If you put the block away I doubt it will make its way inside the car again.
Ive seen guys get too carried away and actually reuse the old pistons in a worn out bore cause "well its original", "value" etc. Good gawd.
Gimme a good proper rebuild anyday over that. I kept my 73 all # match didnt enjoy ownership..it meant spit when I sold it.
Buyer said "I could care less" and saw his point. 2 mos later he had a new motor, paint etc and sold it for much more a year later.
Last edited by cv67; Sep 14, 2018 at 08:10 AM.
Le Mans Master
Joined: Mar 2004
Posts: 7,472
Likes: 1,494
From: Little Rock AR
Do not deck the block. That operation is not required unless the engine blew a head gasket and eroded the surface. Leave it alone - Regardless of what the shop tells you, the guy running the mill will remove the numbers. Happens all the time.
Team Owner
Joined: Mar 2002
Posts: 44,642
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From: Huntsville AL
Find another machinist, better yet don't deck the block because I bet it's not required they just want to make money off you. A good machine shop can deck the block and not machine the number pad.
Drifting
Joined: Dec 2002
Posts: 1,591
Likes: 111
From: North Brunswick NJ
First, take detailed pix of the pad. If the machine shop, for whatever reason decks them, I believe re-stamping is OK according to NCRS (if you give a shi_) rules as long as you are not trying to counterfeit the build to something other what originally came in the car. If you go through the trouble of re-stamping, make sure you go with a quality outfit. Nothing jumps out at you as like a poorly attempted re-stamp.
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
If the measurements the machinist takes says it needs decked then do it. You want a head that seals or make guys on the internet happy?
Deck heights on brand new blocks can be off, a 50 yr old one thats been rebuilt before? Do it.
Deck heights on brand new blocks can be off, a 50 yr old one thats been rebuilt before? Do it.
Le Mans Master
Joined: Jan 2006
Posts: 6,505
Likes: 139
From: Butler Pa
There are many reasons to deck a block, but very few of them are necessary.
Race Director
Joined: Mar 2016
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From: Napa Valley California
Why would you "NOT" deck the block in a rebuild?
It's part of doing a quality job of the machining of the block.
That's like not line boring or balancing.
If your machinist has been in business for a long time, has a good reputation, knows what he is doing and he recommends decking the block then do it.
I would do it anyway just to make sure all mating surfaces are true and square.
Ask the machinist to save the numbers and take photos before and after the decking.
If the numbers are wiped from the block ask that they are re-stamped and photograph them again to document.
My 73 BB is a numbers matching car.
The only thing that will be original on the motor will be the block and I'm sure the numbers will be wiped from the pad.
If I could find a nice 4 bolt block I might pick it up just to start my rebuild before I pull the body off the chassis.
If I do I'll sell the motor and TH-400 as a running unit because the auto is going to be replaced by a TKO-600 5 speed anyway.
It's part of doing a quality job of the machining of the block.
That's like not line boring or balancing.
If your machinist has been in business for a long time, has a good reputation, knows what he is doing and he recommends decking the block then do it.
I would do it anyway just to make sure all mating surfaces are true and square.
Ask the machinist to save the numbers and take photos before and after the decking.
If the numbers are wiped from the block ask that they are re-stamped and photograph them again to document.
My 73 BB is a numbers matching car.
The only thing that will be original on the motor will be the block and I'm sure the numbers will be wiped from the pad.
If I could find a nice 4 bolt block I might pick it up just to start my rebuild before I pull the body off the chassis.
If I do I'll sell the motor and TH-400 as a running unit because the auto is going to be replaced by a TKO-600 5 speed anyway.
Melting Slicks
Joined: Mar 2010
Posts: 2,268
Likes: 374
From: Randolph nj
LET ME REPEAT MYSELF .... DO NOT DE-VALUE YOUR CAR BY LETTING THEM MILL THE NUMBERS OFF THE BLOCK .... find a new machinists that has the knowledge to keep them on and mill the block accordingly . I’m not a total persuist but when it comes to taking a 1/3 of the value out of the car buy milling the numbers off the block and then having to prove that they were there once won’t sell it for me ....
Administrator
Joined: Jul 2000
Posts: 53,980
Likes: 6,207
From: About 1100 miles from where I call home.
It doesn’t matter if the car is rare. Changing the heads, a simple bolt on change, is a terrible, terrible excuse to permanently harm the value of your car. A head change has nothing to do with anything. It doesn’t matter whether you care about “matching numbers” or not. You will, unequivocally, hurt the value of your car by decking the numbers.
You are also asking the wrong question. Yes you can find someone who can re-stamp the pad after it’s been ruined, but you are completely forgetting about the fact that the original broach marks will have been lost and anyone that’s ever looked at the pad will now reject the new restamp in an instant. I am going to guess you had not planned for finding an artisan who can replicate the correct pad surface before you even get to the restamp point. And don’t kid yourself into thinking you can “explain” that it looks funny because it was decked and restamped, but honest, it’s the right numbers.
Do not make this mistake. Too many people are way too ready to tell you numbers matching doesn’t matter. It’s not true.
Find another machinist. I know people with rebuilt engines that have found a machinist that would not ruin the value of their cars.
You are also asking the wrong question. Yes you can find someone who can re-stamp the pad after it’s been ruined, but you are completely forgetting about the fact that the original broach marks will have been lost and anyone that’s ever looked at the pad will now reject the new restamp in an instant. I am going to guess you had not planned for finding an artisan who can replicate the correct pad surface before you even get to the restamp point. And don’t kid yourself into thinking you can “explain” that it looks funny because it was decked and restamped, but honest, it’s the right numbers.
Do not make this mistake. Too many people are way too ready to tell you numbers matching doesn’t matter. It’s not true.
Find another machinist. I know people with rebuilt engines that have found a machinist that would not ruin the value of their cars.
Administrator
Joined: Jul 2000
Posts: 53,980
Likes: 6,207
From: About 1100 miles from where I call home.
I should add this... if you are stuck between a choice of multiple machinists telling you that they can’t fix your engine properly and losing your original numbers forever, don’t do either.
Your dollars in that scenario will be more wisely spent on a brand new crate engine that you can modify to your hearts delight, with a full warranty, and you can run it out until it doesn’t run any more with no concerns. Put the original block aside for the eventual sale.
Ive done this in the past and it’s worked out beautifully. Win/win.
Your dollars in that scenario will be more wisely spent on a brand new crate engine that you can modify to your hearts delight, with a full warranty, and you can run it out until it doesn’t run any more with no concerns. Put the original block aside for the eventual sale.
Ive done this in the past and it’s worked out beautifully. Win/win.
Team Owner
Joined: Jun 2000
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From: Southbound
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